With heat accumulators, the current production of solarthermal power stations can be independent of the vageries of the Sun. Solarthermal power stations can supply energy even at night and in overcast conditions.

Credit:
DLR/Markus-Steur.de.

The energy system of the future must be sustainable. Ideally, it should not generate emissions that affect the climate or be at risk of major malfunctions or hazardous environmental impact. Energy should be economical and socially acceptable and its provision should be reliable. Highly efficient technologies are required to produce and use this energy.

The DLR energy research programme is focusing on these aims. To acquire renewable energies economically, we are researching and developing materials, processes and technologies for the efficient use of solar and wind energy. DLR solar energy research focuses on the development and optimisation of solar thermal power plants, which convert concentrated solar radiation into heat and electricity. This includes the development of existing and new technologies, as well as the qualification and standardisation of solar power plants and their individual components. In addition, we are researching solar-chemical techniques to produce chemical energy sources, i.e. solar fuels. Regarding wind energy research, we are paying particular attention to the smart rotor; at the forefront are questions regarding its aerodynamics, aeroacoustics, aeroelastics, structure and production, as well as its intelligent operation and control. The characterisation of wind fields is also being investigated.

A sustainable energy system, whereby the sun and wind provide energy dependent on the weather, relies on efficient and economical energy storage. Researchers at DLR are developing and investigating new thermal and electricity storages, as well as chemical storages that can store energy in the form of fuels. Thermal storages in the high temperature range can provide great savings in power plants or industrial processes, and are perfect additions to solar thermal power plants, in order to operate these around the clock. Electrochemical energy storages (batteries) are key components both for use in stationary energy systems and also in electromobility. Chemical storages (fuels, i.e. hydrogen) are ideal for long-term storage and for mobile applications.

In addition to energy storage, highly efficient energy converters provide an important additional and flexible option for energy systems. Power from chemical storage should only be generated in highly efficient converters. To this end, we are working on efficient and flexible gas turbines on the one hand - in the range from kilowatts to megawatts - and fuel cells and electrolysers on the other. Specifically, research objectives in the combustion process of gas turbines involve fuel and load flexibility, emissions and efficiency, with a focus on the use of alternative fuels and micro gas turbine power plant concepts. In the case of fuel cells and electrolysers, the focus lies on materials, service life, system compatibility and costs.

To attain the best possible future energy system in terms of smooth and efficient interactions that is also highly flexible and stable, we are developing and optimising technical components and their integration within the energy system technology. This includes technologies for sector coupling (electricity - heat - transport) and individual system-relevant technologies that are used in the decentralized networked structures of buildings and cities. Flexibilisation measures are being explored to synchronise fluctuating electricity generation with power consumption demands. The portfolio is rounded out with work on the low and medium voltage levels of power grids, and also includes new approaches in the field of power grid technologies and smart energy management solutions as well as the integration and assessment of system services.

We are investigating the use of new types of materials for all energy technologies, such as functional and ceramic composite materials for high temperature applications, aerogels as electrode materials in batteries and fuel cells, and thermo-electric materials that allow heat to be converted into electrical energy.

DLR research also includes multiple areas related to energy systems analysis, which is required to understand and design future overall energy systems. For instance, energy meteorology helps to determine the potential of renewable energy sources. On this basis meteorological information forecasting tools for improved control of electricity supply systems can be developed. Based on scenario analyses, the potential of (future) energy technologies for the overall energy system is identified. Thus concepts for sustainable energy supply and their implications for the energy system are analysed. Similarly, we also use network and system modelling and agent-based simulation to optimise energy systems. Control instruments, business models, funding mechanisms and strategies for market launches can be developed and tested, based on our methods and skills. Our aim is to design a future sustainable energy system that corresponds best to multi-dimensional criteria, as well as to point out best paths and efficient regulation to get there.